The present invention relates to a downwind type wind turbine which generates electricity in the state that a rotor is disposed downwind and more particularly to a downwind type wind turbine in which disposition of a transformer constituting substation or transformation equipment is improved.
Wind power generation is known as renewable energy together with photovoltaic generation and its need is enhanced from the point of view of reduction of CO2, so that installation of wind turbines is advanced rapidly. Horizontal-axis wind turbines are divided broadly into upwind type wind turbines having rotor disposed upwind and downwind type wind turbines having rotor disposed downwind according to arrangement of rotor in the direction of wind. Most of wind turbines installed for wind power generation are upwind type wind turbines.
As described above, although the upwind type wind turbines are mainstream currently, when the rotation surface of rotor of the upwind type wind turbine is to be arranged perpendicularly to blowing-up wind in mountain regions or on the sea where blowing-up wind from the underside of wind turbine is increased, the rotor collides with a support post supporting the wind turbine due to its shape and accordingly the rotation surface of rotor cannot be arranged perpendicularly to blowing-up wind. As a result, energy of wind cannot be used for rotation of rotor effectively and the generation efficiency of electricity is reduced.
On the other hand, in case of the downwind type wind turbine, since electricity is generated in the state that rotor is disposed downwind, the rotor does not collide with the support post even if the rotation surface of rotor is arranged perpendicularly to blowing-up wind, so that energy of wind can be used for generation of electricity efficiently as compared with the upwind type wind turbine and so the downwind type wind turbine has precedence. Accordingly, installation of downwind type wind turbines is desired on the sea or in mountain regions, for example, where blowing-up wind is superior.
However, only a limited installation space of wind turbine is available in the mountain regions or on the sea described above in the first place and to be able to install the wind turbine it would be necessary to make it possible to install the wind turbine even in a reduced space. As a measure of reducing the space concretely, it is conceivable to dispense with a building for storing the transformer therein, which is usually individually set up outside the wind turbine.
Generally, a well-known technique that transformer is stored inside the wind turbine to save space is described in JP-A-2006-9596, for example. In the technique described in JP-A-2006-9596, a storage room is provided in a support post and substation/switching equipment composed of transformer and switching apparatus is provided in the storage room.